Extracorporeal Irradiation Of LymphExtracorporealdiation of lymph as a technique for immunosuppression is undergoing clinical trial at the University of Texas Medical Branch, Galveston.On March 30, 1967, a 52-year-old man received a cadaver renal transplant. Irradiation of the patient's lymph, circulated through an external radiation source, has been the only immunosuppressive therapy before and after surgery.It is, of course, too early to assess the value of this technique. The patient, however, has shown no sign of early rejection, Harry E. Sarles, MD, and co-workers reported to the annual meeting of the American Society for Artificial Internal Organs.With this technique, lymph from the cannulated thoracic duct is exposed to strontium 90 (90Sr) and then reinfused into the body.The radiation source, with a surface delivery of 40 rads/sec is placed in a wooden block. A plastic tube inserted through the base of the block carries the